Apparatus for yarn twisting



Dec. 4, 1951 L, EWING 2,577,571

. APPARATUS FOR YARN TWIS'I'ING Fiied Sept. 28, 1949 IN V EN TOR. I

A T TORNE'Y Patented Dec. 4, 1951 APPARATUS FOR YARN TWISTING Alvin L. Ewing, Chester, Va., asslgnor to E. I. du Pont de Nemours and Company, Wilmington, Del., a corporation of Delaware Application September 22, 1949, Serial N 0. 117,167 4 Claims. (01. 57-59) This invention relates to yarn twisting and more particularly to an improved throwing bobbin cap especially adapted for use on an uptwister machine.

In the twisting of rayon and other synthetic filament yarns by unwinding the yarn from a bobbin mounted and revolved on a spindle at high speed and slowly winding it up on a constant peripheral speed spool, commonly referred to as an uptwister, great difliculty has heretofore been encountered in retaining the cap on the spindle and the bobbin. Due to the high rate of rotation of the spindle and bobbin, the cap has a tendency to fiy off the spindle causing damage to the cap, to the yarn being twisted and not infrequently causing injury to the operator. Caps have heretofore been provided with various types of looking means but for one reason or another these have not been entirely satisfactory.

Accordingly, it is an object of this invention to provide a bobbin cap structure with means for locking the cap to the spindle of the twisting machine. Another object is to provide in 9. bobbin cap a simple, inexpensive, efficient looking ing, silver soldering, welding or it may be pressfitted thereon, screwed on, or made as an integral part of the spindle. The purpose here is to provide at the end of the spindle a plurality of circumferential grooves 3 into which one of the lock wires 4 and 4' will become engaged by the action of centrifugal force as the spindle and bobbin are revolved. The twister cap 5 is fastened by three symmetrically spaced fiat-headed tubular rivets 6 to a base plate 7 which in turn is fastened to bushing 8 by means of a wooden dowel 9. The base plate 1 may be made of various materials and is preferably die cast. Die cast aluminum has been quite satisfactory. The rivets 6 may be stainless steel or brass or any other suitable fastening means may be used.

The bobbin cap 5 is of conventional design stamped from heavy sheet metal, such as brass, stainless steel, nickel, and may, if desired, be

plated as with chromium and polished, especially around the outer edge which the yarn contacts to reduce running tension and prevent degradation of the yarn. The bushing 8 is preferably long relative to its diameter to provide greater device which is effective even when rotated at bility and to have plenty of room for engagevery high speeds but which is easily releasable for removal of the bobbin cap from the spindle. Other objects will be apparent from the description that follows and from the drawings wherein:

Figure 1 is a sectional view through the improved cap of this invention; and

Figure 2 is a partial plan view, taken on 22 of Figure of the cap showing the locking arrangement.

As shown in the above drawings, the objects of this invention are accomplished by providing a throwing bobbin cap with a plurality of locking means actuated by centrifugal force into engagement with circumferential grooves located near the tip end of the spindle. The bobbin cap has fixed to it a bushing in which is positioned a lock wire or lock wires. The unit comprising the cap, the bushing and the lock wire is adapted to fit on a spindle or spindle sleeve which has a plurality of grooves cut circumferentially and which fits tightly on the spindle carrying the yarn package. When the cap is in proper position in respect to the yarn package, a lock wire fits into one of the grooves and is held there by the centrifugal force acting on it as the entire unit is rotated.

Referring to Figure 1 the usual twister spindle I is fitted at the tip with a spindle sleeve 2. This sleeve 2 may be fastened to the spindle by solderment with any of the circumferential grooves 3 on the sleeve 2 that may be called for due to variations in bobbin lengths. This bushing 8 is preferably made from impregnated wood such as are used for oilless bearing materials and sold under trade-names as Nolu, Arguto, etc. The lock wires 4 and 4', which may be, one, two or more in number, preferably two, are of such diameter as to easily engage one of the circumferential grooves 3 of sleeve 2. They are positioned in slots l0 and I 0' of bushing 8. Generally, it is preferred to have the diameter of the grooves on the sleeve a few thousandths of an inch larger than the diameter of the wire. A spring steel wire, tempered and rust proofed, has proved very satisfactory and each wire is preferably shaped as shown in Figure 2 with the ends of the wire spot-welded or soldered together at H with silver solder after the wire is placed in the bushing. This is desirable as a safety measure. In case the wire should wear in two, it will be held to the cap and the two parts will not fiy oi as they would if the ends were not fastened together. As the entire assembly rotates at high speed, the centrifugal force acting on the relatively heavy joined ends of the lock wires keeps the lock wires in proper locking contact with the grooves. As shown, in the figures, only one wire fits in a groove at a given time. The other rests on a ridge and is ready for insertion into a groove 3 upon slight vertical movement of the cap unit in respect to the sleeve 2. This cuts the distance between grooves in half for the engagement of each wire and spacing is kept as close as possible.

In operation, the operator may unlock the cap by simply pressing the lock wires sideways and toward each other until they strike the edge of the slot I in the bushing at which position lock release will be indicated by a slight snap. The wires are moved radially as shown in .Figure 2 by the dotted lines [2. In a preferred embodiment which gives more positive locking, each lock wire is provided with a slight curve or radius at It to contact more surface of the groove 3 than would a straight section of wire. After the wires have been released the cap can be easily removed by lifting it vertically. In placing the cap on a bobbin mounted on the spindle, it should be allowed to settle until it engages the top of the'bobbin all around and when the spindle is started up, one of the lock wires will engage one of the several circumferential grooves on the sleeve.

In assembling, the lock wires 4 and 4 are inserted into the bushing 8 being positioned in the slot l0 and each wire is soldered at l I. This unit is then pressed through the cap 5 into the base 1 which is fixed permanently on the cap by rivets 6. The bushing 8 is then secured by the wooden dowel 9. The sleeve 2 is fitted on the spindle I carrying yam package H. The unit comprising the cap, bushing, lock wires and base is then placed on the sleeve until proper positioning is obtained in respect to the yarn package. Upon rotation of the bobbin or application of centrifugal force thereby, the lock wires go into locking position. Upon stopping and release of the wires, they automatically remain out of. locking position until centrifugal force is again applied. The cap may be removed or replaced without further handling of the lock wires.

The use of this invention on an uptwister machine substantially eliminates fiying bobbin caps and hence reduces operator hazards as well as equipment loss and degradation of yarn usual in yarn twisting areas. By reason of this automatic action and simplicity of construction it provides effective, inexpensive protection.

4 Any departure from the procedure described herein which conforms to the principles of the invention is intended to be included within the scope of the claims below. I claim:

1. In combination, a grooved spindle; a bob- ,bin cap having a bushing adapted to fit on said spindle, the bushing having a slot and positioned therein locking means cooperating, by action of centrifugal force, with said grooved spindle to hold said cap on said spindle.

2. Apparatus for locking 9. bobbin cap to a spindle comprising, in combination, a bushing fixed to said cap having a slot and positioned therein a lock wire; and a spindle having grooves, said lock wire adapted to fit in said grooves and to be held there by the centrifugal force acting on said wire during rotation.

3. Apparatus for looking a bobbin cap to a spindle comprising, in combination, a bushing fixed to said cap; a slot in said bushing and positioned therein a lock wire; a sleeve adapted to fit snugly on said spindle and grooves in said sleeve to make locking contact with said lock wire, said wire being curved at the said contact.

4. Apparatus for looking a bobbin cap to a spindle comprising, in combination, a bushing fixed to said cap; a slot in said bushing and positioned therein a lock wire; a sleeve adapted to fit snugly on said spindle and grooves in said sleeve cooperating with said lock wire to make locking contact, said wire being curved at the said contact and having a relatively heavy end.

ALVIN L. EWING.

REFERENCES CITED The following references are ofrecord in the file of this patent:

UNITED STATES PATENTS Number Name Date 271,521 Royle, Jr. et al Jan. 30, 1883 1,574,689 Prince-Smith et a1. Feb. 23, 1926 1,870,202 Gollong Aug. 2, 1932 FOREIGN PATENTS Number Country Date 245,580 Great Britain Jan. 14, 1926 

